1 /*
2 * HEVC MP4 to Annex B byte stream format filter
3 * copyright (c) 2015 Anton Khirnov
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #include <string.h>
23
24 #include "libavutil/intreadwrite.h"
25 #include "libavutil/mem.h"
26
27 #include "avcodec.h"
28 #include "bsf.h"
29 #include "bsf_internal.h"
30 #include "bytestream.h"
31 #include "hevc.h"
32
33 #define MIN_HEVCC_LENGTH 23
34
35 typedef struct HEVCBSFContext {
36 uint8_t length_size;
37 int extradata_parsed;
38 } HEVCBSFContext;
39
hevc_extradata_to_annexb(AVBSFContext * ctx)40 static int hevc_extradata_to_annexb(AVBSFContext *ctx)
41 {
42 GetByteContext gb;
43 int length_size, num_arrays, i, j;
44 int ret = 0;
45
46 uint8_t *new_extradata = NULL;
47 size_t new_extradata_size = 0;
48
49 bytestream2_init(&gb, ctx->par_in->extradata, ctx->par_in->extradata_size);
50
51 bytestream2_skip(&gb, 21);
52 length_size = (bytestream2_get_byte(&gb) & 3) + 1;
53 num_arrays = bytestream2_get_byte(&gb);
54
55 for (i = 0; i < num_arrays; i++) {
56 int type = bytestream2_get_byte(&gb) & 0x3f;
57 int cnt = bytestream2_get_be16(&gb);
58
59 if (!(type == HEVC_NAL_VPS || type == HEVC_NAL_SPS || type == HEVC_NAL_PPS ||
60 type == HEVC_NAL_SEI_PREFIX || type == HEVC_NAL_SEI_SUFFIX)) {
61 av_log(ctx, AV_LOG_ERROR, "Invalid NAL unit type in extradata: %d\n",
62 type);
63 ret = AVERROR_INVALIDDATA;
64 goto fail;
65 }
66
67 for (j = 0; j < cnt; j++) {
68 int nalu_len = bytestream2_get_be16(&gb);
69
70 if (4 + AV_INPUT_BUFFER_PADDING_SIZE + nalu_len > SIZE_MAX - new_extradata_size) {
71 ret = AVERROR_INVALIDDATA;
72 goto fail;
73 }
74 ret = av_reallocp(&new_extradata, new_extradata_size + nalu_len + 4 + AV_INPUT_BUFFER_PADDING_SIZE);
75 if (ret < 0)
76 goto fail;
77
78 AV_WB32(new_extradata + new_extradata_size, 1); // add the startcode
79 bytestream2_get_buffer(&gb, new_extradata + new_extradata_size + 4, nalu_len);
80 new_extradata_size += 4 + nalu_len;
81 memset(new_extradata + new_extradata_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
82 }
83 }
84
85 av_freep(&ctx->par_out->extradata);
86 ctx->par_out->extradata = new_extradata;
87 ctx->par_out->extradata_size = new_extradata_size;
88
89 if (!new_extradata_size)
90 av_log(ctx, AV_LOG_WARNING, "No parameter sets in the extradata\n");
91
92 return length_size;
93 fail:
94 av_freep(&new_extradata);
95 return ret;
96 }
97
hevc_mp4toannexb_init(AVBSFContext * ctx)98 static int hevc_mp4toannexb_init(AVBSFContext *ctx)
99 {
100 HEVCBSFContext *s = ctx->priv_data;
101 int ret;
102
103 if (ctx->par_in->extradata_size < MIN_HEVCC_LENGTH ||
104 AV_RB24(ctx->par_in->extradata) == 1 ||
105 AV_RB32(ctx->par_in->extradata) == 1) {
106 av_log(ctx, AV_LOG_VERBOSE,
107 "The input looks like it is Annex B already\n");
108 } else {
109 ret = hevc_extradata_to_annexb(ctx);
110 if (ret < 0)
111 return ret;
112 s->length_size = ret;
113 s->extradata_parsed = 1;
114 }
115
116 return 0;
117 }
118
hevc_mp4toannexb_filter(AVBSFContext * ctx,AVPacket * out)119 static int hevc_mp4toannexb_filter(AVBSFContext *ctx, AVPacket *out)
120 {
121 HEVCBSFContext *s = ctx->priv_data;
122 AVPacket *in;
123 GetByteContext gb;
124
125 int got_irap = 0;
126 int i, ret = 0;
127
128 ret = ff_bsf_get_packet(ctx, &in);
129 if (ret < 0)
130 return ret;
131
132 if (!s->extradata_parsed) {
133 av_packet_move_ref(out, in);
134 av_packet_free(&in);
135 return 0;
136 }
137
138 bytestream2_init(&gb, in->data, in->size);
139
140 while (bytestream2_get_bytes_left(&gb)) {
141 uint32_t nalu_size = 0;
142 int nalu_type;
143 int is_irap, add_extradata, extra_size, prev_size;
144
145 if (bytestream2_get_bytes_left(&gb) < s->length_size) {
146 ret = AVERROR_INVALIDDATA;
147 goto fail;
148 }
149 for (i = 0; i < s->length_size; i++)
150 nalu_size = (nalu_size << 8) | bytestream2_get_byte(&gb);
151
152 if (nalu_size < 2 || nalu_size > bytestream2_get_bytes_left(&gb)) {
153 ret = AVERROR_INVALIDDATA;
154 goto fail;
155 }
156
157 nalu_type = (bytestream2_peek_byte(&gb) >> 1) & 0x3f;
158
159 /* prepend extradata to IRAP frames */
160 is_irap = nalu_type >= 16 && nalu_type <= 23;
161 add_extradata = is_irap && !got_irap;
162 extra_size = add_extradata * ctx->par_out->extradata_size;
163 got_irap |= is_irap;
164
165 if (FFMIN(INT_MAX, SIZE_MAX) < 4ULL + nalu_size + extra_size) {
166 ret = AVERROR_INVALIDDATA;
167 goto fail;
168 }
169
170 prev_size = out->size;
171
172 ret = av_grow_packet(out, 4 + nalu_size + extra_size);
173 if (ret < 0)
174 goto fail;
175
176 if (extra_size)
177 memcpy(out->data + prev_size, ctx->par_out->extradata, extra_size);
178 AV_WB32(out->data + prev_size + extra_size, 1);
179 bytestream2_get_buffer(&gb, out->data + prev_size + 4 + extra_size, nalu_size);
180 }
181
182 ret = av_packet_copy_props(out, in);
183 if (ret < 0)
184 goto fail;
185
186 fail:
187 if (ret < 0)
188 av_packet_unref(out);
189 av_packet_free(&in);
190
191 return ret;
192 }
193
194 static const enum AVCodecID codec_ids[] = {
195 AV_CODEC_ID_HEVC, AV_CODEC_ID_NONE,
196 };
197
198 const AVBitStreamFilter ff_hevc_mp4toannexb_bsf = {
199 .name = "hevc_mp4toannexb",
200 .priv_data_size = sizeof(HEVCBSFContext),
201 .init = hevc_mp4toannexb_init,
202 .filter = hevc_mp4toannexb_filter,
203 .codec_ids = codec_ids,
204 };
205